Abstract:
To facilitate the design and realization of Printed Electronics (PE) analog and digital circuits – both for PE-only and Hybrid Electronics – we present a Process Development Kit (PDK) for our Fully-Additive All-Air Low-Temperature printing process. Our printing process is a ‘green’ process that features simplicity, low-cost, on-demand, and scalability and is printable on flexible substrates. These attributes are to a large extent because our process involves only additive (vis-à-vis subtractive or mixed subtractive-additive) steps – hence ‘Fully-Additive’. Further the processing is completely in air (vis-à-vis requiring nitrogen, etc.), and the maximum temperature is a low 120°C, hence permitting printing on very-low cost plastic films and other flexible films.
A PDK provides valuable insight to circuits and systems designers, and is imperative for the practical design and simulation of printed circuits, including manufacturability and the implications thereto. Our PDK embodies a printed transistor model which is simple, accurate (including accounting for layout) and fully compatible with industry-standard integrated circuit design automation tools, and embodies passive elements. Our PDK further embodies process variations and matching based on various layout techniques; both based on our Fully-Additive All-Air Low-Temperature printing process where the variations are very-low in the context of PE – ±4.9% µ (carrier mobility) and ±0.43V Vth (threshold voltage). For manufacturability, process variations need to be modeled and the printed circuits in general would need to be designed to accommodate said variations. These considerations are challenging because the process variations of printed circuits are large (in the perspective of conventional silicon) and conventional (silicon-based) circuit design techniques to accommodate large variations are largely inapplicable due to the inapplicability of negative feedback. On the basis of our PDK, several fundamental analog and digital PE circuits are designed and printed. The measured parameters of said printed circuits agree well with that obtained from simulations based on our PDK, thereby verifying the efficacy of our PDK.